KR980010566A - Manufacturing method of thin film transistor liquid crystal display - Google Patents

Abstract

The present invention describes a method of manufacturing a TFT-LCD (thin film transistor liquid crystal display). It is easy to etch the metal layer and the silicon film by separate etching without etching the metal layer and the silicon film at the same time as the four-mask process, and the manufacturing cost can be reduced by reducing the number of process steps by the three-mask process.

Description

Manufacturing method of thin film transistor liquid crystal display

The present invention relates to a semiconductor device, and more particularly, to a method of manufacturing a TFT-LCD (thin film transistor liquid crystal display) which simplifies the process. Currently used image display devices include a cathode ray tube (CRT) and a flat panel element such as a liquid crystal display (LCD), a plasma display (PDP), and a fluorescent display (VFD). The liquid crystal display device has a simple matrix type or an active matrix type. In a liquid crystal display device using the electro-optic properties of a liquid crystal, the basic driving principle is a liquid crystal display device in which an electric field And the external light flowing into the liquid crystal display device is intercepted and transmitted according to the change of the arrangement to form an image.

FIG. 2g is a cross-sectional view illustrating a method of manufacturing a TFT-LCD (thin film transistor liquid crystal display) according to the prior art. Reference numeral 11 denotes a TFT substrate, 13 13a 13b a gate, 15 an insulating film, 17 an amorphous silicon film, 19 · 19a an amorphous silicon film doped with impurities, 21 · 21a a metal layer, And 25 denotes a protective film, respectively.

Referring to FIG. 1A, a first mask (not shown) for forming a gate is formed on a TFT substrate 11 on which a gate conductive layer (not shown, patterned in a subsequent process 13, 13a, 13b) is formed A gate 13a is formed in the TFT channel portion on the TFT substrate 11, and a gate 13b is formed in the storage capacitor portion.

Referring to Fig. Ib, an insulating film 15, an amorphous silicon film (not shown, patterned at 17 in a subsequent process), an impurity-doped silicon film (not shown) are formed on the TFT substrate 11 on which the gates 13a and 13b are formed A step of forming an amorphous silicon film (not shown, patterned at 19 in a subsequent process), a metal layer (patterned at 21 in a subsequent process, not shown), and a step of forming a predetermined region of the storage capacitor portion in which the gate 13b is formed The amorphous silicon film / amorphous silicon film doped with the metal layer / impurity is photolithographically etched by using a second mask (not shown) of the amorphous silicon film / amorphous silicon film 19 / The first metal layer 21 is formed of Cr (Cr) to form a source / drain region, and the insulating film 15 is formed of SiNx.

Referring to FIG. 1C, a transparent conductive film (ITO, not shown, patterned at 23 in a subsequent process) is formed on the resultant product, a step of forming a predetermined region on the gate 13a of the TFT channel portion The transparent conductive film 23 / the metal layer 21a / the amorphous silicon film 19a by photolithography the transparent conductive film / metal layer 21 / amorphous silicon film 19 using a mask (not shown) .

Referring to FIG. 1d, a process of forming a protective film (not shown, patterned at 25 in a subsequent process) with SiNX is formed on the entire surface of the resultant product. Subsequently, the protective film 25 is formed by photolithography using a fourth mask (not shown) pattering the protective film as in the gate pad portion / data pad portion of FIG. 1F.

As described above, it is difficult to etch the metal layer and the silicon film at the same time, and the process is complicated because four masks are used.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of manufacturing a TFT-LCD (thin film transistor liquid crystal display) which simplifies a process.

1A to 1F are cross-sectional views illustrating a conventional method for manufacturing a TFT-LCD (thin film transistor liquid crystal display).

2A to 2G are cross-sectional views illustrating a method of manufacturing a TFT-LCD according to the present invention.

According to an aspect of the present invention, there is provided a method of manufacturing a TFT-LCD (thin film transistor liquid crystal display) in which a TFT channel portion and a storage capacitor portion are formed on a TFT (thin film transistor) substrate, Forming a gate on the TFT substrate by photolithography using a first mask to form a gate; Forming an insulating film, an amorphous silicon film, and an amorphous silicon film doped with an impurity in this order on the TFT substrate on which the gate is formed; Depositing a photoresist over the entire surface of the TFT substrate; Patterning the photoresist layer by back exposure using the gate as a mask; Etching the amorphous silicon film and the amorphous silicon film doped with the impurity using the patterned photoresist as a mask; Forming a first transparent conductive film (ITO) film, a metal layer, and a second transparent conductive film on the resultant product by sequentially removing the photoresist film; A step of photo-etching the metal layer with the second transparent conductive film using a second mask in which a predetermined region on the gate is opened in the TFT channel part; Etching the second transparent conductive film; Etching the impurity-doped amorphous silicon film and the first transparent conductive film using the patterned metal layer as a mask; Depositing a protective film on the entire surface of the resultant product; And etching the protective layer and the metal layer using a third mask having a predetermined area of the storage capacitor portion opened. [7] The method of manufacturing a thin film transistor liquid crystal display (TFT-LCD) according to claim 1,

The present invention can easily etch the metal layer and the silicon film by etching them separately without etching the metal layer and the silicon film as in the conventional four-mask process, and reduce the manufacturing cost by reducing the number of processes by the three-mask process. The present invention will be described in detail.

2A to 2G are cross-sectional views illustrating a method of manufacturing a TFT-LCD (thin film transistor liquid crystal display) according to the present invention. Reference numeral 51 denotes a TFT substrate, 53 53a 53b a gate, 55 an insulating film, 57 an amorphous silicon film, 59 59a an amorphous silicon film doped with impurities, 61 61a 65 a transparent conductive film, 63 denotes a metal layer, and 67 denotes a protective film.

Referring to FIG. 2A, a first mask (not shown) for forming a gate is formed on a TFT substrate 51 on which a gate conductive layer (not shown, patterned in 53. 53a, 53b in a subsequent process) is formed A gate 53a is formed in the TFT channel portion on the TFT substrate 51, and a gate 53b is formed in the pixel portion, by photolithography the gate conductive layer.

Referring to FIG. 2b, an insulating film 55, an amorphous silicon film (not shown, patterned at 57 in a subsequent process), and an impurity-doped silicon film (not shown) are formed on the TFT substrate 51 on which the gates 53a and 53b are formed A step of depositing a photoresist film (not shown) on the entire surface of the TFT substrate 51, a step of depositing a photoresist film (not shown) on the entire surface of the TFT substrate 51, The amorphous silicon film and the amorphous silicon film are etched using the patterned photoresist as a mask to form an amorphous silicon film 57 doped with an impurity and an amorphous silicon film 57 doped with an impurity, And the step of forming the film 59 are sequentially performed.

The insulating film 55 is formed of SiNx.

Referring to FIG. 2C, the photoresist layer is removed and the resultant is coated with a first transparent conductive film (ITO) 61, a metal layer (not shown, patterned as 63 in the subsequent process), a second transparent conductive film The second transparent conductive film and the metal layer are photolithographically etched by using a second mask in which a predetermined region on the gate 53a is opened in the TFT channel portion, The process of forming the transparent conductive film 65 and the metal layer 63 is performed. The metal layer 63 is made of chromium (Cr) for forming the source / drain regions.

Referring to FIG. 2d, the first transparent conductive film 61 and the amorphous silicon film 59 doped with an impurity are etched using the metal layer 63 as a mask, Etching is performed to form the amorphous silicon film 59a doped with the channel and the first transparent conductive film 61a and the impurity.

Referring to FIG. 2E, a protective film (not shown, patterned in a subsequent process) is deposited on the entire surface of the resultant product, a third mask (not shown) having a predetermined area of the storage capacitor portion The protective layer and the metal layer 63 are etched using the mask layer 63 to form the protective layer 67 and the metal layer 63a.

2F shows the completed gate pad portion according to the present embodiment, and FIG. 2G shows the data pad portion, respectively. It is obvious that the present invention is not limited thereto and that many modifications are possible within the technical scope of the present invention by those skilled in the art.

As described above, the TFT-LCD (thin film transistor liquid crystal display) manufacturing method of a semiconductor device according to the present invention is easy to etch by separating and etching the metal layer and the silicon film, The manufacturing cost can be reduced by reducing the number of processes by every mask process.

Claims (1)

1. A method of manufacturing a TFT-LCD (thin film transistor liquid crystal display) in which a TFT channel portion and a storage capacitor portion are formed on a TFT (thin film transistor) substrate, comprising: forming a first mask for forming a gate on the TFT substrate on which a gate conductive layer is formed Forming a gate on the TFT substrate by photolithography; Forming an insulating film, an amorphous silicon film, and an amorphous silicon film doped with an impurity in this order on the TFT substrate on which the gate is formed; A step of depositing a photoresist layer on the entire surface of the TFT substrate, a step of patterning the photoresist layer by back exposure using the gate as a mask, the step of patterning the amorphous silicon layer and the amorphous silicon layer doped with the impurity using the patterned photoresist layer as a mask, Forming a first transparent conductive film (ITO) film, a metal layer, and a second transparent conductive film in this order on the resultant product by removing the photoresist film; A step of photo-etching the metal layer with the second transparent conductive film using a second mask in which a predetermined region on the gate is opened in the TFT channel part; Etching the second transparent conductive film; Etching the impurity-doped amorphous silicon film and the first transparent conductive film using the patterned metal layer as a mask; Depositing a protective film on the entire surface of the resultant product; And etching the protective layer and the metal layer using a third mask having a predetermined area of the storage capacitor portion opened. ※ Note: It is disclosed by the contents of the first application.